Noise From Front Driver's Side - PeachParts Mercedes-Benz Forum

Jmana · #1 11-07-2005, 10:42 PM

There is a noise coming from the front driver's side of my 85 300SD that keeps getting worse, but I cannot figure out where it's coming from. The noise is really hard to describe, I would describe it as a "crunching" noise, but it's more like a very dull squeak, like the noise that bad shocks make. It also makes a thump that is felt on the floor and in the brake pedal. The noise is really noticible when going slow and putting on the brakes, but it is also heard occasionally when just going down the road. It will also do it when I turn the steering wheel back and forth. I cannot replicate the noise when it is not moving, I've tried bouncing the front end up and down but no noise. Sometimes it will do it if I push the car from side to side. Putting on the brakes when not moving will not make the noise, but even going a few miles an hour and putting on the brakes the noise is really loud. The only thing I have done to the front is about 2 months ago I put new calipers, pads, rotors, and repacked the bearings. The noise began a few days ago, and now is to the point where I am worried that there is something seriously wrong. I took the wheel off tonight and checked the bearings again, and they look ok (I didn't take them out), and the wheel seems solid and moves smoothly so I don't think it's the bearings going out. Originally I thought maybe a bolt was loose at the caliper, but they are all tight. The steering assembly seems tight also. I am at a loss as to what could be causing this noise. Has anyone else had this happen? Any suggestions on where to look to find where it's coming from?

Ralph69220d · #2 11-08-2005, 10:25 AM

My 220d is my first mb, so i don't know how the 330sd is constructed. On the 220d there is a bracket a couple feet rear from the exhasust manifold. If that bracket were loose the exhasust pipe might slap back and forth making noise. Did this problem arise immediately after swapping out the old brake system? Did you overtighten the wheel bearings? If overtightening the wheel bearings this would reduce bearing / race life, but it doesn't intuitively seem it would result in the noise you describe under those conditions. I mention the exhaust bracket, as this would be consistent with hearing the noise while pushing the car from side to side. It sounds as if a relative movement of drive train to chassis is the problem. The exhaust suspension system problem would be consistent with this and the most easily checked..

Jmana · #3 11-08-2005, 04:47 PM

Well, I have narrowed it down to the front drivers side spring, or something that is attatched to the spring. For some reason it wouldn't make the noise when pushing down on the car, but when I stepped on the bumper it made the noise and it definitely is coming from around the spring. I had a diesel spill in that side of the engine, so I don't know if maybe that caused something to squeek? I'm not really too concerned about it right now, because I am just happy it's not a bearing or caliper issue.